Lapping machine truing apparatus



June 9 194-2. s, N E 2,285,717

LAPPING MACHINE-TRUING APPARATUS Filed March 16, 1940 4 Sheets-Sheet 1 HEREEH T5 [N055 Mum- June 9, 1942. H. s. INDGE 2,285,717

LAPPING MACHINE -TRUING APPARATUS Filed March 16, 1940 I 4 Sheets-Sheet 4 66 6G 82. 1 82 19 Q g OH 80 80 P 3 78 E ZQ 15 6 Q '75 72 3 \Q 63 13 73 4 77 77 \yfl 74 ig 6 HERE'EF? T fif/VUEE Patented June 9, 1942 narrmc mcnmn 'riwmc APPARATUS Herbert S. Indie, West hero, Mass, assignor to Nortonflompany, Worcester, Mass., a corporation of Massachusetts Appllcation'March 16, 1940, Serial No. 324,309

Clalms.

The invention relates to lapping machines, and more particularly to a lapping wheel truing apparatus for simultaneously trulng the opposed faces of a pair of lapping elements.

One object of the invention is to provide a simple and thoroughly-practical lapping machine. .A further object of the invention is to provide an improved truing apparatus for truing the plane surface on a lapping wheel. Another object of the invention is to provide animprovedlapping wheel truing apparatus whereby the opposed faces of a pair of lapping wheels may be simultaneously trued. A further object of the invention is to provide an improved hydraulically controlled lapping wheel truing apparatus. A further object of the invention is toprovide an improved adjusting device-for .relatively adjusting the position of the truing tools. Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts, as will be exemplified in the structure to be hereinafter described,

and the scope of the application of which willbe indicated in the following claims.

In the accompanying drawing in which is shown one of various possible embodiments of the mechanical features of the invention,

Fig. 1 is a side elevation of the improved lapping machine, having parts broken away to more clearly show the construction;

Fig. 2 is a fragmentary cross sectional view taken approximately on the line 22 of Fig. 1,

showing a plan view of the lapping wheel truing apparatus;

Fig. 3 is a fragmentary plan view of the truing tool supporting arm having parts broken away and shown in section to more clearly show the adjusting mechanism;

Fig. 4 is a fragmentary side elevation of the 99 of Fig. 8, through one of the adjusting screws for the truing apparatus bracket, showing the threaded bushing and its actuator in elevation; and

Fig. 10 is a fragmentary section similar to Fig. 9, but showing the threaded bushing and its actuator in section.

Referring more particularly to the embodiment illustrated, the lapping machine may be constructed in its general aspects similar to the lapping machine illustrated in my prior U. S. Patent No. 2,103,984 dated December 28, 1937.

This machine, as illustrated, may comprise a base l0 which rotatably supports a lower lapping wheel H. The base 10 is provided with an upwardly extending column l2 having an outwardly extending horizontal portion l3 which rotatably supports a vertical spindle M. Th spindle It carries a rotatable lapping wheel l5 which is connected-to its lower erld by means of a supporting plate l6.

Power may be obtained from any suitable source, such as an overhead drive shaft or an electric motor mounted on the machine. A belt drive has been shown comprising a driving belt 20 which serves to rotate a pulley 2|. The inner portion of the pulley 2| is formed as one part of a cone clutch. A slidably mounted cone clutch member 22 serves to mate with the clutch face within the pulley 2| to transmit a rotary motion to a rotatably mounted drive shaft 23 which is journalled'in suitable bearings 24, 25, 26 and 21 in the base Ill. The clutch member 22 is slidably keyed to the shaft 23. When the clutch member 22 is in the full line position (Fig. 1), no power is transmitted to the shaft 23. When it is desired to rotate the shaft 23, the cone clutch member 22 is moved toward the right (Fig. 1) into engagement with the cone clutch member within the pulley 2| so as to cause rotation of the shaft 23.

In order that the clutch may be readily actuated from an operating position adjacent to the front of the machine, a pivotally mounted control lever 28 is supported on a stud 29 on the base 10 of the machine. The lower end of the lever 28 is connected by a stud 30 with a link 3|. The link 3| is-in turn connected by a stud 32 with the forward end of a slidably mounted rod 33., The rod 33 is slidably journalled in'bearings 34 and 35 which are fixedly mounted on the base ID. The rod 30 supports a vertically extending arm 36 which is yoke-shaped at its upper end and engages a groove 31 formed in a hub which is integral with the clutch member 22. By movement of the control lever 28 in a counterclockinto j;he position illustrated in Fig. 1, the clutch member 22 is disengaged, thus stopping the rotation of the shaft 23 so as to stop not only the rotation of the lower lapping wheel II and the upper lapping wheel II but also the work supporting cage.

The shaft 23 is provided with a worm 46 which meshes with a worm gear [4| mounted on the lower end of a vertical rotatably mounted shaft 42. The shaft 42 is connected by means of a universal joint 43 to the lower end of a shaft 44.

Theshaft 44 is preferably a telescopic shaft and is connected at its upper end by a universal joint 45' with the lower end of arotatable shaft 46 which is rotatably supported in suitable bear-v ings (not shown) in a bracket 46 which is ad-' justably. mounted on top. of the column. l2. The shaft 46 is provided with a multiple V- groove pulley 56 which is connected by a multiple V-belt with a multiple V-groove pulley 52 which is fixedly mounted on a rotatable sleeve (not shown). The rotatable sleeve is slidably keyed to an upwardly extending projection of the spindle 4 so that when the clutch 22 is engaged, the vertical spindle |4 supporting the upper lap will be rotated.

The sleeve above mentioned is provided with a rack bar 55 which meshes with a gear 56 mounted on a rotatable shaft 51 by means of which the upper lapping wheel l5 may be raised and lowered to the desired. extent. In the preferred construction, a hydraulically operated mechanism is provided comprising a pair of In order that the laps H and I5 may be main tained with their operative faces in a predetermined lapping condition, a suitable truing apparatus is essential to permit a truing of the operative faces of the laps when desired and necessary. In the embodiment of the invention illustrated, a pivotally mounted truing apparatus is provided in which a truing tool is through an aperture in the bracket 63. The screw adjusting devices 64, 66 and 66 are provided with aslight amount of clearance to facilitate adjustment of the bracket 63 about the axis of the stud 61 as a pivot. A pair of bosses 66 and 66 are fixedly mounted on the column of the machine. A pair of adjusting screws I6 and II extend through screw threaded apertures in the boms 66 and 66, respectively, and bear againstportions of the bracket 63. By means of the adjusting screw devices 64, 65 and 66, together with the adjusting screws 16 and II, the bracket 63 may be accurately and precisely adjusted so that the axis of the shaft 66 may be adjusted in all directionsrelative to the axis of the lap supporting spindles l4.

The adjusting devices 64, 65 and 66 are identical in construction, consequently only one of these devices has been .shown in detail in Figs. 9 and 10. The .screw 66 passes through a central aperture in a sleeve 12 and is screw threaded to the column l2. A clearance aperture is provided in the sleeve 12 to facilitate lateral adjustmounted on a rock arm which is arranged to be swung through an arcuate path across the operative face or faces of the lap. As illustrated in the drawings, this mechanism comprises a verti cally mounted rotatable shaft 66 which is supported in bearings 6| and 62 which are formed integral with a bracket 63. The bracket 63 is adjustably fixed to the side face of the column |2 by means of three adjusting screw devices 64, and 66. The adjusting devices 64, 65 and 66, which are identical in construction, are provided for aligning the bracket 63 relative to the side face of the column l2.

The bracket 63 is also supported by a stud 61 ment of the bracket 63. The sleeve I2 is provided with a screw thread 13 on its outer periphery which meshes with or mates with a correspondingly shaped screw threaded aperture within Q bushing I4. The bushing 14- is journalled in an aperture 15 formed in the bracket 63. The bushing "is provided with an integral flange l6 at its lower end which fits within a recess 11 formed in the.under surface of the bracket 63. The upper end of the sleeve 14 is provided with clutch teeth 16 which are arranged to mate with clutch teeth I9 formed in the lower end of a rotatable sleeve 66. The sleeve 66 surrounds the bolt or screw 66 and is provided with an outwardly extending integral flange 6| which is provided with a plurality of radially extending holes 62 about its periphery.

When it is desired to adjust the position of the bracket 63 to align the axis of the shaft 66 relative to the'axes of the lapping wheels H and. [5, the screws 64, 65 and 66 are loosened and a spanner wrench is inserted in one of the holes 62 in the flange 6|. The bushing 66 is then rotated to transmit a rotary motion through the clutch teeth |6|6 to rotate the threaded sleeve 12 and thereby adjust the position of the bushing 14 so as to adjust the position of the bracket 63 as desired. When the desired adjustment has been accomplished, the screw 66 is again tightened to lock the bracket 63 in a flxed position relative to the column 2 and the .base l6.

Each of the screw adjusting devices 64, 65 and 66 is provided with corresponding adjustments and each is provided with flanged bushings 6|, 63 and 64, respectively, which are arranged to be engaged by spanner wrenches in the manner above described to adjust the position of the bracket 63 at three symmetrically arranged points. It will be readily apparent from the foregoing disclosure that by loosening any one of the screws 64, 65 and 66 and adjusting the flanges 6|, 63 and 64 of the bushings 66, the position of the bracket '63 may be readily adjusted relative to the column 2 so as to position the axis of the shaft 66 in' the desired relationship with the axes of the rotatable lapping wh'els II and I5.

A swinging arm 65 is provided with an enlarged end portion 66 having an aperture which trips the shaft 66. One side of the enlarged head 66 of the arm 65 is provided with a slot 61 which which is fixed to the column l2 and which passes allows the end portion 66 to expand and contract so that it may be readily clamped in position on the shaft 88 by means of clamping screws 88 and 89. It will be readily apparent from the foregoing disclosure that by means of the clamping screws 88 and 89, the arm 85 may be adjusted angularly relative to the shaft 68 and may also be adjusted in a vertical direction to position the arm in the desired and predetermined position.

The outer end of the arm 85 is provided with a pair of opposed aligned diamonds or truing tools 98 and 9I, respectively, which are arranged simultaneously to true the opposed operative faces of the lapping wheels II and I5, respectively. It is desirable to provide means for readily adjusting the position of the diamonds relative to the swinging arm. The outer end of the swinging arm 95 is provided with a pair of pivotally mounted arms 92 and 93, respectively, which are rotatably supported by a sleeve 94 (Fig. 3). A binder screw 95 passes through a central aperture within the sleeve 94 and carries at one end a plate 96 which is held against rotation by means of a pin 91 which is fixedly supported by the arm 92. A collar 98 is mounted at the other end of the screw 95. This collar is set into a counterbored portion of the arm 93 and a manually operable binder or nut 99 is provided whereby the stud 95 may clamp the collars 96 and 98 and the arms 92 and 93 in rigid adjusted position on the swinging supporting arm 85. I

To facilitate adjustment of the arms 92 and 93 to position the truing tools 98 and 9|, respectively, as desired, the arm 85 is provided with an outwardly extending member. I88 which serves as a support for a pivotally mounted stud IN. The arm 93 also supports a stud I82 which is arranged parallel to the stud I8I. An adjusting screw I83 is provided with a right and lefthand screw threaded portion projecting in opposite directions from the central knurled adjusting portion. The right-hand and left-hand threaded portions of the screw I83 are threaded into correspondingly threaded apertures in the studs I8I and I82, respectively, so that by rotation of the screw I83 when the nut 99 is released the arm 93 may be adjusted relative to the swinging arm 85 to facilitate adjustment of the position of the diamond or truing tool 9|.

Similarly, a stud I84 is also supported by the extending portion I88 of the arm 85. A stud I85 is carried by the arm 92 and an adjusting screw I86 having oppositely extending right and lefthand screw threaded portions is screw threaded into the studs I84 and I85, respectively. Adjustment of the screw I86 when the nut 99 is loosened facilitates an adjustment of the arm 92 to position the diamond or truing tool 98 as desired. After the truing tools or diamonds 98 and 9I have been adjusted to the desired extent, the binder nut 99 is tightened to lock the truing tools in adjusted position.

The diamonds or truing tools 98 and 9I are supported, respectively, by nibs I I8 and II I which fit within apertures formed within the arms 92 and 93, respectively. Set screws H2 and H3 are provided on the arms 92 and 93, respectively, to lock the nibs, I I8 and III, respectively, in fixed positions relative to the arms 92 and 93. In the preferred form, as illustrated in the drawings, the diamond or truing tools 98 and 9I are arranged in substantial alignment with each other and project vertically above and below the truing.

tool arm assembly so that they will simultaneously engage and true the opposed faces of the lapping wheels II and I5, respectively.

A suitable power. operated mechanism is provided for oscillating the arm to traverse the truing tools 98 and 9| simultaneously across the opposed faces of the lapping wheels II and I5 at a slow uniform rate to true the operative faces thereof to maintain the desired lapping surfaces. In the preferred construction, a hydraulically actuated mechanism is provided to swing the arm through an arcuate path. A fluid pressure cylinder I28 is pivotally mounted on a stud I2I which is supported by a bracket I22 which is in turn fixedly mounted on the column I2. A piston I23 is slidably mounted within the cylinder I28 and is connected by means of a piston rod I24 with a stud I25. The stud I25 is supported at one end of a rock arm I28, the other end of which is fixedly supported on the upper end of the rotatable shaft 68. It will be readily apparent from the foregoing disclosure that when fluid is admitted to the cylinder I28, caus- I24 and stud I25 and the rock arm I28, which serves to rock the vertical shaft 68 and thereby to swing the arm 85 and the truing tools 98 and 9| across the operative faces of the rotatable lapping wheels II and I5, respectively.

A fluid pressure system is provided to supply fluid under pressure to operate the piston I23. This system comprises a reservoir I38 formed within the base I8 of the machine. A motor driven pump I3I drives fluid from the reservoir I38 through a pipe I32 and forces fluid under pressure through a pipe I33 to a control valve I34 which will be hereinafter described. A fluid pressure relief valve I35 is connected in the pipe line I33 to return excess fluid under pressure through an exhaust pipe I36 to the reservoir I98.

The control valve I 34 is preferably a rotary type valve which is formed integral with the cylinder I 28. The cylinder I28 is provided with an upwardly extending hollow boss I48 having a cap I H fixedly mounted thereto. The valve I34 comprises a valve chamber I42 formed within the boss I48. A valve rotor I43 is rotatably mounted within the chamber I42 and is held in its uppermost position by means of a ball I44 and a spring I45 (Fig. 5) to maintain the valve rotor I43 in operative contact with the under surface of the cap I4I. A manually operable lever I46 is provided to operate the valve rotor I43 to reverse the direction of flow of fluid to the cylinder I28 so as to control the oscillatory movement of the truing tools. The control lever I46 is fixedly mounted on the upper end of a bushing I41, the lower reduced end portion of which. is rotatably supported within a central aperture in the cap I4I. A strip of flat stock I48 is located at its upper end in a slot formed in a cover plate I49. The lower end of the strip I 41 engages a slot formed in the upper surface of the valve rotor I43. When the valve control lever I 46 of the valve I 34 is moved, the flat strip I48 I In the position of the valve shown in the draw ings, fluid under pressure from the pump I3I passes through the pipe I33 into the valve chamber I42 and passes upwardly through a passage or'hole I58 formed in the valve rotor I43 (Fig. 5) and through a U-shaped passage I5I in the cap I and through a. passage I52 into a cylinder chamber I53 formed at the left-hand end of the piston I23 to move toward the right (Fig. 5),

which movement serves to oscillate the arm 65 in a counterclockwise direction (Fig. 2) During the movement of the piston I23 toward the right (Fig. 5), fluid within a cylinder chamber I54 exhausts through a passage I55 through a U-shaped passage I56 in the cap I and passes along an arcuate groove I51 formed in the upper surface of the valve rotor I43. Fluid passing through the arcuate passage I51 passes through a U-shaped passage I56 formed in the cap I and through a passage I56 through a needle type valve I60 which in the present case is formed as a cylindrical end portion having an angular slabbed-ofi end face to provide a precise adjustment of the exhaust aperture. Fluid passing through the valve I66 enters a chamber-IN and from there passes out through a pipe I62 which V exhausts into the reservoir I30. The valve [60 comprises a valve stem I63, a portion of which is' screw threaded into a portion of the housing. A knurled knob I64 is adjustably mounted on the outer end of the stem I63 and is normally held in a locked position by means of a second knurled nut I65. Theneedle valve I66 serves to control the rate 01' exhaust of fluid from the cylinder chamber I54, thus controlling the rate of oscillation or traverse of the truing tools supporting arm 85 as it moves the diamond or truing tools 66 and 9| across the faces of the lapping wheels.

When the valve rotor I43 is rotated in a clockwise direction (Fig. 7) to reverse the direction of flow of fluid within the system, a vertically extending aperture or hole I16 in the valve rotor I43 swings in a counterclockwise direction into alignment with the U-shaped passage I56 so that fluid under pressure in the valve chamber I42 passes upwardly. through the passage I10, through the U-shaped passage I56, through the During this shifting movement of the valve rotor I43, the arcuate groove I51 moves out of contact with the U-shaped passage I56, thus cutting U-shaped passage I12 so that as the piston I23 moves toward the left (Fig, 5), fluid within the cylinder chamber I53 exhausts throughthe passage I52, through the U-shaped passage I5I, through the arcuate groove "I, and through the U-shaped passage I12 and through a passage I13 Y passage I55, into the cylinder chamber I54, to ,move the piston I23 toward the left (Fig. 5).

which connects with an adjustable needle valve I into the valve chamber I6I may be varied as desired to control the rateor movement of the piston I23 toward the right (Fig. 5)

It will be readily apparent from the foregoing disclosure that the needle valves I66 and I14 serve independently to adjust the rate of movement or the piston I23 as it moves toward the right and left. respectively, in oscillating the truing tools 60 and 3| across the operative faces of the lapping wheels II and I5. By providing an' independent adjustment of the movement of the truing tools in the opposite direction, compensation may be made for the diflerential in piston area on opposite sides of the piston I23 so that the rate of movement in either direction may be equal or uniform or, if desired, the rate of movement may be adjusted so that the truing tools travel at one rate when the arm 65 is oscillated in one direction and at a diflerent rate when the arm is oscillated in the opposite direction. It will be readily apparent from the foregoing disclosure that each operative stroke of the truing tools may be independently adjusted so as to produce any desired and predetermined result.

In order to facilitate adjustment of the needle valves I66 and I14, adjustable stop devices are provided for accurately positioning the valves when desired. As illustrated in Fig. 6, the knurled adjusting knob I16 is provided with a stop pin I66 which is arranged in the path 01 a stop lug Ill. The stop lug I 6I is supported on a pivotally mounted member I62 which is supported by a stud I63 carried by a bracket I64 which is in turn flxedly mounted relative to the valve casing or boss I46. It will be readily apparent from the foregoing disclosure that the valve stem I15 may be rotated by the knurled knob I16 until the stop pin I66 engages the stop lug I6I, thus providing a rapid adjustment of the valve I14 to a predetermined operative position to produce the desired traversing speed of the diamond ortruing tool in one direction. Due to the fact that the knurled knob I16 is adjustably supported on the valve stem I15, the position of the stop pin I66 may be readily varied by loosening the locking nut I11 and then repositioning the knurled knob I16 to obtain the desired precise adjustment of the valve.

The valve I66 is provided with a similar stop adjusting device comprising a stop pin I65 which is carried by the knurled knob I64. This stud is arranged to engage a stop lug I66 carried by a member I61 which is pivotally supported by a stud I66. The stud I66 is in turn supported by a bracket I66 which is fixedly supported relative tothe valve casing or boss I46 and the cylinder- I26. The mounting for the knurled knob I64 and its locking nut I65 is identical with the corresponding parts of the valve I14, consequently sectional details of this valve have not been shown (Fig. 6). By adjusting the position oi. the knurled knob I64, the location of the stop pin I65 may be adjusted relative to the stop lug I66. Ii it is desired to adjust the position of the valves I14 and I66 by an amount greater than one turn of the valve stem, the members I62 and I61, respectively, may be swung in a counterclockwise and clockwise direction, respectively, to move the stop lugs "I and I66, respectively, out of the path of the stop pins I66 and I65 respectively, so that the knobs I16 and I64, respectively may be rotated more than one turn as desired. It will thus be seen that by manipulation of the valves I66 and I14, the speed of oscillation of the diamonds 60 and 3| may be independently and precisely adjusted to the same or to a different speed as the arm 85 moves in opposite directions.

The operation of the improved lapping machine truing device will be readily apparent from the foregoing disclosure. The position of the shaft 68 is first adjusted by manipulation'of the screw adjusting devices 64, 65, 66, Ill and H so that its axis is parallel to the axes of the lapping wheels H and I5. In this position of the shaft 68, the oscillatable truing arm 85 may be swun in a path normal to the axis of the lapping wheels II and I5. The upper lapping wheel IE will then be moved downwardly into a truing position with an adjustable stop screw I98 which moves with the spindle M in engagement with a stop abutment I9! which is fixedly mounted with respect to the column l2. The diamonds or truing tools 88 and 9| are then adjusted in the manner above described to position them in relation with the operative faces of the lapping wheels. The arm 85 may then be adjusted to the desired vertical position and swung about the axis of the shaft 60 to position the truing tools adjacent to the peripheral surface of the lapping wheels, after which the clamping screws 88 and 88 may be clamped to lock the arm 85 rigidly with respect to the shaft 80. After these adjustments have been made, the truing operation may be accomplished by actuation of the valve control lever I48 which serves to control the admission to and exhaust of fluid from the cylinder chambers I53 and I54 to oscillate the arm 85 and the truing tools 90 and 8| simultaneously to true the opposed operative faces of the lapping wheels H and I5. By manipulation of the needle valves I68 and I'M, respectively, the rate of oscillation of the truing tools and their supporting arms may be independently adjusted so a that the arm travels at the same rate of speed in opposite directions or at different rate of speed as desired for the particular truing operation.

It will thus be seen that there has been provided by this invention apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as"many changes might be made. in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting'sense.

I claim:

7 1. In a lapping machine having a base, a retatable lapping wheel and a truing apparatus comprising a bracket on said base, a rock shaft supported thereby, an oscillatable arm adjustably supported on said shaft, a truing tool adjustably supported on said arm, means to oscillate said arm to pass the truing tool across the operative face of said lapping wheel, and a-plurality of screw adjusting devices forming a threepoint support between the bracket and base whereby the position of said shaft may be adjusted into parallelism with the axis of said lapping wheel.

2. In a lapping machine truing apparatus having a movable member, a pair of independent, pivotally mounted truing tool supporting arms supported on said member, aligned opposed truing tools on said arms, independent screw and nut adjustments independently to adjust the position of said arms and truing tools relative to said member, and a manually operable clamping clamping device whereby said arms and truing tools may be simultaneously clamped in adjusted position. v

4. In a lapping machine truing apparatus having a movable member, a pair of independent, pivotally mounted arms, a pivot stud connecting one end of each of said arms with said member, independent adjusting devices between the other ends of said arms and said member, aligned opposed truing tools on said arms, and a manually operable clamping device associated with said pivot stud for clamping said arms and truing tools in adjusted positions.

5. In a lapping machine truing apparatus having a movable member, a pair of independent, pivotally mounted arms, a pivot stud connecting one end of each of said arms with said member, independent adjusting devices between the other ends of said arms and said member, aligned opposed truing tools on said arms, said truing tools being located on said arms between the pivot stud and said adjusting devices, and a manually operable clamping device associated with said pivot stud for clamping said arms and truing tool in adjusted positions.

. HERBERT S. INDGE. 

